On Friday, August 14, 2015 at 1:40:04 PM UTC-5, Oren wrote:
On Fri, 14 Aug 2015 11:31:57 -0700 (PDT), Uncle Monster
wrote:

I wonder if your Bios battery could be dead or dying. Something like that can cause computer dementia. Ż\_(?)_/Ż

True. If dead it would likely ask for a date and time, but the BIOS
found his drive, showed up again as the master when he hit DEL into
the BIOS.

If the voltage gets low, the date and time may remain unaffected but I've seen weird behavior that's mitigated when a new battery is installed. Sometimes you must default the BIOS and start over. There are also cosmic rays and Bush you can blame it on. O_o

[8~{} Uncle BIOS Monster